Diagnosing Heart Disease, Faster

Adding a test can help doctors diagnose heart disease among people who arrive in the emergency room with chest pains. The test helps patients get home faster — but the jury's still out on whether it's good for them overall

When a patient comes to the emergency room with chest pains, doctors need to figure out quickly if there’s a cardiac problem or if, instead, the cause of the pain is something more benign, like heartburn. That’s not always easy, and it’s not always cheap. But adding one extra test, a new study shows, may help doctors determine sooner whether seemingly low-risk patients in fact have heart disease — cutting the average time patients spend in the hospital by several hours.

That’s the good news. The bad news is that adding the test gives patients an extra dose of radiation, and it doesn’t necessarily improve other outcomes: patients’ overall risk of a cardiovascular event or death, or the total cost of the hospital visit. The study has prompted a debate among doctors about how many tests is too many, and what the threshold should be for adding a new test to already-expensive emergency care.

The new study comes from researchers at nine U.S. hospitals, who collaborated to test whether care is improved among chest-pain sufferers by adding CCTA (coronary computed tomographic angiography) to a battery of existing diagnostic tests. The researchers’ evaluation of CCTA is published this week in the prestigious New England Journal of Medicine (NEJM).

The study tracked 1,000 emergency patients with no known history of heart disease, and whose first round of hospital tests — an electrocardiogram and a blood test for the biomarker troponin — didn’t seem to show an obvious heart attack. Half of the study participants were randomized to standard care, and the other half to standard care plus CCTA diagnostic testing.

CCTA combines CT scanning with the use of an intravenous contrast material, and allows hospital imaging staff to create detailed images of the blood vessels that supply the heart. Armed with those test results, emergency doctors have additional information to distinguish which of the patients who report chest pains have heart disease, and which ones do not. That information can then guide subsequent hospital care — or, if appropriate, may suggest that a patient is not at risk of a cardiac event and can be discharged.

Patients who got the CCTA testing in the NEJM study were able to leave the hospital on average 7.6 hours sooner than patients who did not — and four times as many as normal were discharged directly from the emergency department.

The debate is over whether extra testing is necessary at all for people whose first-round test results show no sign of heart attack. Hoffman and his co-authors found that the intervention group was no more likely to experience averse events as a result of the extra diagnostic screening than the group that did not get the test. People who received CCTA were also no more likely to have been sent home with an overlooked heart condition, or to have suffered a cardiovascular event one month later. However, those results are driven by the extremely low rates of cardiovascular events among the study participants to begin with.

Less than 1% of the study participants actually had a heart attack, and none of them died, cardiologist Rita Redberg writes in an editorial that accompanies the NEJM article. “[T]he question is not which test leads to faster discharge of patients from the emergency department, but whether a test is needed at all.”

And patients receiving CCTA did receive an extra dose of radiation from the diagnostic procedure. That could raise the risk of cancer in the future.

In the end, whether it’s a good idea to add the new test may be a matter of priorities. For hospitals, earlier discharge of patients can help free up patients, but the total cost of care was the same for patients with or without CCTA (at around $4,000) because the savings from discharging some patients sooner was offset by the upfront cost of the test and more expensive care for people testing positive on CCTA for heart disease.

For doctors, CCTA may be a big help. “[It allows] clinicians to focus the use of resources on patients with heart disease,” study author Hoffmann told reporters. They can rest easy sending home the lowest-risk patients, and concentrate on the higher-risk ones.

But for patients, the answer is less clear. They need to weigh the benefit of going home sooner against the risk of extra radiation, and the possibility that, if the test is positive for heart disease, there may be a bunch more tests to come.